Dry battery and cell with improved anode



March 24, 1953 J. J. COLEMAN ETAL DRY BATTERY AND CELL WITH IMPROVEDANODE Filed D60. 16, 1948 IN VEN TORS.

the portion of the U-shaped element which joins the two legs thereof,the bend of the U, forms the top of the cell. The sides of thiselectrode are open; that is, the two leg portions are substantiallycoextensive and cotermin-ous with the broad surfaces of the mix block 3,leaving the side edges thereof uncovered by the electrode. An opening 8is provided in the top portion of the electrode exposing the portion ofthe bibulous separator element which underlies and spans the opening.Thus, the entire top of the cell is covered either by the separatorelement '5 alone or by a portion of the negative electrode in additionto the separator. Mix block 3 i not exposed at the top of the cell.

The negative electrode assembly is illustrated in Fig. 3 in the form inwhich it appears before being bent to the shape in which it is used inthe cell. This assembly, which includes separator element 5, is formedfrom a rectangular blank of sheet metal. Opening 8 is punched at theproper location at the middle of the blank, a lug 9 being left for thepurposes hereinafter described. The bibulous separator element, whichmay be a sheet of starch-coated pap r, for example, is then laid uponthe punched blank and the marginal portions 5a of the separator turnedback over the edges of the blank to overlap the marginal portions of theblank on the side opposite to that covered by the separator. Thiselectrode assembly is-then ready to be formed to the shape in which itwill be used in the cell wherein the separator element 5 will form alining for the electrode 4 to separate the same from the mix block 3.

In assembling the cell, the mix is inserted between the legs of theformed electrode. This may be done by directly extruding a. slug of thematerial into the space between the legs of the electrode, or pre-formedblocks of mix may be inserted in any manner suited to productiontechniques. It is not necessary to observe the usual close tolerances incarrying out this operation since the electrode assembly itselfestablishes the limit of insertion of the mix materia1 into the cell.The carbon rod positive terminal 6 is then inserted by driving the rodthrough the separator 5 in the opening 8 of the negative electrode. Itis not necessary to provide a hole in the separator for this purposewhen the proper material, such as paper of suitable strength, is used asthe separator element, the mix being sufiiciently firm to support, theseparator as the carbon is driven through. Insertion of the carbonterminal in this manner insures a close fit between the rod and theseparator so that no opening is left through which the mix may pass. Ifdesired, the carbon rods may be pointed to more readily pierce theseparator, but this is not necessary.

Each cell is finally placed in a pocket or envelope 1 of a suitable filmmaterial which covers the four sides and the bottom of each cell. Aconvenient method for providing such a covering for the cells isindicated in Fig. 4 showing a continuous trough of film material intowhich the cells are inserted, the two sides of the trough being broughttogether and sealed between adjacent cells. If the cells have beenproperly spaced and oriented in carrying out this process, the string ofcells so formed may be brought together in juxtaposed relationship byaccordion folding the string, as indicated in the drawing.

If desired, insertion of carbon rods 6 may be deferred until after thecells have been covered by the film material.

In fabricating th battery from the cells thus produced, the desirednumber of cells may be placed within a tray Ill and electricallyinterconnected by means of lugs 9 which may be bent to engage thepositive terminal of the adjacent cell. A suitable thermoplastic sealingmaterial Il may then be poured upon the tops of the cells and a finalmoisture-proof coating I2 may be applied, if desired, by dipping theentire sealed unit in microcrystalline wax or other suitable moistureresistant coating material. Suitable means, not shown, must, of course,have been provided for bringing out the battery terminals for connectionto an external circuit.

It is desirable that the cell elements be held together firmly toprovide good physical contact between mix, separator, and negativeelectrode. One function of tray I0 is to serve this purpose. The roundedtops of electrodes 4 permit any necessary flexing as the cells arebrought together under some pressure and inserted in the tray.-

Alternatively, the juxtaposed cells may be held together by tape whichalso serves as a protective covering. With this arrangement, properlyapplied, the tray and top seal may be eliminated, a single dip inmicrocrystalline wax, bi-wax, or other suitable material sufficing tocomplete and seal the battery unit.

Numerous alternative forms of negative electrode may be employed withoutdeparting from the principle of the invention. Examples of suchalternative forms are illustrated in Figs. 5-8.

In the negative electrode 4 illustrated in Fig. 5, an opening isprovided at each side of the electrode instead of a single opening inthe middle portion in the manner described above. This arrangement hasthe advantage of providing greater separation between terminal lug 9 andthe positive terminal of the cell, the eventual location of which isshown at E- in dotted lines. This is particularly desirable in smallcells for the reason that the top sealing material may more readily andcompletely cover and seal the elements when so separated. As in the caseof the cells of Figs. 1 and 2; the entire top of the cell in which theform of electrode of Fig. 5 is employed will be covered by the separatorelement and, in part, by a portion of the negative electrode.

The electrode assembly illustrated in Fig. 6 is similar to that of Fig.l, the difference being the addition of a bottom flange l3 which extendsfrom the end of one leg of the electrode and is intended to underlie andsupport the mix block at the bottom of the cell. This flange increasesthe active area of the electrode and leaves only the two narrow sides ofthe mix block of the cell uncovered.

The electrode 4 of Fig. 'l'consists of only one side and a top portion.This electrode, while simpler than that of the other embodiments of theinvention, provides the desired top covering for the mix block andthereby achieves the principal object of the invention.

Where it is desired to employ a separator element which is of suchstrength that it is not possible to pierce it by the carbon rod in themanner above described, a small opening M may be punched in theseparator at the eventual location of the carbon terminal of the cell, ashown in the electrode assembly of Fig. 8.

From the examples given, many other modifled forms of the invention willoccur to those skilled in the art and no attempt is made herein todescribe all possibilities.

Invention is claimed as follows:

1. In a dry cell, a mix block having opposed broad flat sides and a top,a negative electrode comprising an integral metallic sheet having afirst area co-extensive with a broad side of said mix block and a secondarea extending over the top of said mix block, said electrode beinglaterally coterminous with said mix block and at said first area thereofbeing substantially flat from one lateral edge to the other 1atera1 edgethereof, said second area having an opening therein, a bibuloussheet-form separator element between said mix block and said negativeelectrode and spanning said opening therein, and a positive terminalextending from within said mix block through said opening andpenetrating through said separator.

2. Structure in accordance with claim 1 and including a terminal lugextending from the negative electrode at an edge of said opening, saidlug being integral with said sheet metal element.

3. Structure in accordance with claim 1 wherein said bibulous separatorcomprises a sheet having the marginal portions thereof turned back overthe edges of the negative electrode element and covering at least themarginal portions of the exterior surfaces of said element,

4. In a dry cell, a negative electrode comprising a U-shaped element ofsheet metal having open sides and an opening in the portion joinin thetwo legs thereof, a bibulous separator lining the interior surfaces ofsaid electrode and spanning said opening, a mix block sandwiched betweenthe legs of said lined electrode, and a positive terminal extending fromwithin said mix block through said opening in said negative electrodeand penetrating through said separator.

5. Structure in accordance with claim 4 wherein the portion joining thetwo legs of the U- shaped element is curved.

6. Structure in accordance with claim 4 and including a flange extendingfrom the free extremity of one of the legs of said U-shaped elementunder said mix block toward the free extremity of the other leg of saidelement.

7. In a dry cell, a negative electrode comprising a U-shaped electrodeof sheet metal having two openings in the portion joining the two legsthereof, the first of said openings being located at one side and thesecond of said openings being located at the other side of said portionof said electrode, a bibulous separator lining the interior surfaces ofsaid electrode and spanning both said openings, a mix block sandwichedbetween the legs of said lined electrode, a positive terminal extendingfrom within said mix block through said separator and said firstopening, and a terminal lug extending from the negative electrode at anedge of said second opening.

8. A negative electrode assembly for use in a dry cell comprisin asingle metallic sheet having a fiat rectangular area and a flangeextending at substantially a right angle from the length of one 6 sideof said rectangular area, said sheet being substantially flat from edgeto edge in a direction parallel to said side of said rectangular area,said flange having an opening therein, a terminal lug integral with saidsheet and extending from said sheet at an edge of said opening, and abibulous separator element covering at least the inside surfaces of saidmetallic sheet and spanning said opening.

9. A negative electrode assembly comprising a U-shaped element of sheetmetal having open sides and two openings in the portion joining the twolegs thereof, the first of said openings being located at one side andthe second of said openings being located at the other side of saidportion of said electrode, and a bibulous separator lining the interiorsurface of said electrode and spanning both said openings.

10. A negative electrode assembly in accordance with claim 9 andincluding a terminal lug integral with said element and extendingtherefrom at an edge of said first opening.

11. A dry battery comprising a plurality of juxtaposed cells; each saidcell having a negative electrode comprising a U-shaped element of sheetmetal having open sides and an opening in the portion joining the twolegs thereof which said portion forms the top of the cell, a bibulousseparator lining the interior surfaces of said electrode and spanningsaid opening, and a pair of terminals; means for electrically insulatingthe electrodes of adjacent cells; means for electrically connecting saidcells at their terminals; and

means for holding said juxtaposed cells under The following referencesare of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 14,984 French Nov. 16, 19201,484,926 Benner Feb. 26, 1924 1,490,448 Benner et a1 Apr. 15, 19241,503,285 Parker July 29, 1924 1,582,687 Ramsay Apr. 27, 1926 1,631,568Yngve June 7, 1927 1,775,763 Heise et al Sept. 16, 1930 2,307,762 DelbelJan. 12, 1949 2,307,769 Deibel Jan. 12, 1949 2,475,153 Rock July 5, 19492,480,531 Wilke Aug, 30, 1949 FOREIGN PATENTS Number Country Date198,572 Great Britain June 7, 1923 255,967 Great Britain Aug. 5, 1926557,310 Great Britain Nov. 15, 1943 864,533 France Apr. 29, 1941

